Phonic apparatus.



No. 808,052. PATENTED DEC. 19, 1905. D. HIGHAMK PHONIO APPARATUS.

APPLICATION FILED. JUNE 5.1905.

UNITED A STATES PATENT OFFICF.

DANIEL HIGHAM, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR TO HIGHAMOPHONE COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

PHONIC APPARATUS.

Specification of Letters Patent.

Patented Dec. 19, 1905.

A li ation fil d June 5,1905. Serial No. 263,863.

To all whom it may concern.-

Be it known that I, DANIEL HIGHAM, of Bridgeport, Connecticut, have invented a new and useful Improvement in Phonic Apparatus, which invention is fully set forth in the following specification.

This invention relates to phonic apparatus employing an intermediate friction mechanism between a primary and a secondary vibrating means, such as shown in my United States Patent No. 678,576, of July 16, 1901, and in my allowed United States application filed December 12, 1904, Serial No. 236,609.

In apparatus of the character indicated it has been found that under certain conditions there is a disagreeable squeaking noise resulting from the action of the friction-shoe upon the revolving friction device which tends to a greater or less extent to detract from the perfection of the operation of the apparatus, and particularly is this true when the apparatus is one employed in the reproduction of recorded sounds. In practice one of the preferred forms of friction apparatus consists of a revolving friction-roll having a peripheral V- shaped groove, in which groove there rests a friction-shoe having surfaces contacting with the sides of the V-shaped groove. I have discovered that when the friction-shoe bears evenly and uniformly upon the opposing surfaces of the V-shaped groove the squeaking noises are much diminished, but that when for any reason the friction between the shoe and one side of the groove is increased over that of the friction between the shoe and the other side of the groove the squeaking is much increased. This increase may be caused by the presence of particles of grit or dust upon the friction device or may be due to the lack of uniformity in the composition of the material constituting the friction-roll or the manner in which the friction-shoe is held on the roll. The tendency of the friction-shoe to ride up on one side of the groove results in a side-to-side movement of the friction-shoe in the groove and the production of objectionable noises.

The object of the present invention is to produce a friction device for use in apparatus of the character mentioned which shall be so constructed as to avoid the objectionable noises referred to. I have discovered that if the angle of inclination of the sides of the V- shaped groove is given a certain determined relation to the coefficient of friction between the shoe and the material constituting the friction-roll this side-to-side movement of the shoe will be avoided and the noises 'resulting therefrom avoided. Generally stated, the angle of inclination of the sides of the V- shaped groove should be one whose tangent is approximately equal to the coefficient of friction existing between the shoe and the material constituting the friction roll. I have also found that by giving the link which receives the pull of the shoe a proper position or inclination the said noises may be further diminished, while a still further diminution is obtained by an escape pocket or outlet for dust that accumulates between the shoe and frictionroll. It is also beneficial to make one shoe section of the compound shoe slightly wider than the friction-roll and 'one slightly narrower.

The invention will be best understood by reference to' the accompanying drawings, in which Figure 1 is a side elevation of frictionwheel and jointed frictionshoe in operative position. Fig. 2 is a plan view of Fig. 1. Fig. 3 is a vertical section of Fig. 1 on the line 3 3 of said figure. Fig. 4 is a diagrammatic view serving to illustrate one part of the invention, and Fig. 5 is a broken detail Referring to the figures of the drawings, 1 is a friction-roll of suitable material, as amber, revolved in the direction of the arrow by means of a shaft 2, driven from any suitable source of power. (Not shown.) The shoe, here shown as in two sections 4 and 5, rests in the V-shaped groove 6 and has one of its members 5 in operative relation, through the link 7, with the primary vibratoryineans 20 and its other member in operative relation, through the link 8, with the secondary vibratory means 14.

The two sections 4 and 5 of the frictionshoe are flexibly connected together in the following manner: A lever 9, fulcrumed at 10, is connected to the rear end of shoe-section 4 by a link 11, pivotally joined to the shoe-section 4 and to the lever 19, while a link 12 is also pivotally connected to the lever 9 and the forward end of shoe-section 5, the link 11 being preferably shorter than link 12 and being also connected to the lever 9 at a point nearer the fulcrum 10 than is the link 12. By connecting the shoe-sections in this way comparatively short sections, each somewhat less than one-third of the circumference of the friction-roll 1, may be employed without decreasing the volume of the repro duced sounds. Furthermore, there is a great tendency for the different portions of a long extended shoe composed of two parts connected by a simple link to synchronize and set up squeaking sounds which lend an unnatural tone to the reproduction, and by indirectly connecting the sections in the manner indicated one of the shoe-sections has a slightly greater amplitude of vibration than the other, and this tendency to synchronization is avoided. It has also been found that with this construction the coefiicient of friction at the friction-surface need not be so high to secure the desired volume of the reproduced sounds, and the tendency to squeaking is further reduced for this reason. It has been found best to have the links 8 occupy such a position with respect to the shoe-sections 4 that a line 13 drawn through the point where said link is connected to the shoe-section and through the point where it is attached to the secondary vibrating member 14 will be tangent to the bottom of the V-groove 6 at a point approximately midway between the ends of said shoe-section. By thus arranging the parts the squeaking noise is reduced to a minimum. The same relation is maintained between the link 12 and its shoe-section 5.

In some cases the material, as amber, of which the friction-roll is composed, has fine particles of dust rubbed up by the action of the shoe on the roll, and this dust is liable to and does collect near the rear end of the shoesections and unless provision is made to avoid it gives rise to squeaking noises of the character mentioned. For the purpose of eliminating the squeaking due to thls cause each of theshoe-sectibns 4 and 5 is slightly cut away at the rear end of the friction-face thereof, as indicated at 15 and 16. (See Figs. 1 and 5.) By rear end of the shoesections is meant that end where the frictionroll passes from under the shoe-section. This cut-away part is preferably located just in front of a line drawn through the pivotpoints of the link 11 for shoesection 4 and ink 7 for shoe-section 5, as indicated in Fig. 5, though, if desired, it maybe just in front of a radial line passing through the center of the roll and the point where the link 11 is connected to the shoe-section4 or the link 7 to the shoe-section 5, as shown in Fig. 1. This cut-away space in the shoe-sections affords a place of lodgment for the dust where it will not interfere with or modify the character of the friction between the shoe and roll, and hence eliminates the squeaks due to this cause.

It hasbeen found that by inclining the sides of the V-shaped groove 6 at a proper angle a squeak which sometimes takes place at the rear end of the friction-shoe may be eliminated. This squeak is due to a sideto-side vibration of the rear end of the shoe, caused by the tendency of the shoe to ride up one incline or the other. I have found that this is avoided by making the incline steep enough so that the shoe cannot be sustained upon the incline. Too steep an incline, however, is detrimental to sensitive action of the shoe, and it is therefore important to have the incline only sufficiently steep to overcome this tendency. The correct angle bears a certain relation to the coefficient of friction at the friction contact between the shoe 'and roll and can be readily obtained in the manner shown in Fig. 4, in which the dotted lines represent a portion of the outline of a frictionroller of any suitable material, as of amber. Let A B be a line drawn from the bottom of the V-shaped groove perpendicular to the axis of the friction-roll and B O a line perpendicular to the line A B at B, the length of A B being in proportion to the length. of B C as the coeflicient of friction between the shoe and the roller is to one-that is, assuming, for example, that the coefficient of friction between the shoe and the material constituting the roll is .60 then the length of the line A B is .60 of the length of the line B C. Connect points A and C by the line A C. The angle of inclination of the line A C will be the desired angle of inclination of the sides of the V- shaped groove. Draw the line A D parallel to B O and drop the line C D perpendicular to A D. Then the line C D will be the tan gent of the angle C A D, which is the angle of inclination of the sides of the V-shaped groove. Now since the line A B represents the coeflioient of friction between the shoe and the roll and the line C D is the tangent of the angle of inclination it will be seen that the coeflicient of friction existing between the shoe and the roll is equal to the tangent of the angle of inclination of the sides of the groove.

While theoretically the tangent of the angle of inclination should be equal to the coefficient of friction between the shoe and the roll, it will be understood, of course, that in practice this relation may be slightly departed from, it being only essential that approximately the relation specified should exist. It will also be understood that with the employment of different substances for the frictionroll or the shoe, or both, different coeflicients of friction would exist and that there would therefore necessarily result a different angle of inclination for the sides of the groove.

In friction apparatus of this character it has been heretofore proposed to use a sectional shoe with the links thereof suitably connected together, and I have found that the best results are secured by having the section of the shoe which is connected to the primary vibrating element somewhat narrower than the V-shaped groove in the frictionroll,while the shoesection connected to the secondary vibrating element should be wider than the V-shaped groove in the friction-roll. By this means, and particularly in the case of the shoesection which is wider, I avoid the squeaking noises which result from the rubbing of the sharp edges together. This construction is clearly illustrated in Figs. 2- and 3 and need not be further described.

By combining a friction-roll having a V- shaped groove whose faces are inclined at the proper angle, as hereinbefore described, with a sectional friction-shoe, one at least of whose elements is broader than the V-shaped groove and by indirectly connecting the sections of the friction-shoe together in the manner herein indicated, and having the links which extend from the forward end of the shoesec tions lying approximately in a line tangent to the friction-roll at or about a point midway of the respective sections and employing the cut-away pockets adjacent to the rear ends of the sections, as herein described, I have found it possible to very largely eliminate the objectionable squeaking noises referred to.

What is claimed is 1. In a phonic apparatus employing friction in the manner described, a friction-roller having inclined surfaces, a friction-shoe contacting with and guided by said surfaces, the tangent of the angle of inclination of said surfaces being approximately equal to the coefficient of friction between said shoe and roller when said coefficient is expressed in terms of the angle.

2. In a phonic apparatus employing friction in the manner described, a friction-roller having a peripheral V-shaped groove and a friction-shoe having bearing in said groove,

. the sides of the Vshaped groove having an angle of inclination whose tangent is a proximately equal to the coefficient of friction when said friction is expressed in terms of the angle.

3. In a phonic apparatus employing friction in the manner described, a friction-roller having inclined surfaces, a friction-shoe contacting with said surfaces, the angle of inclination of each of said surfaces being equal to the acute angle at the base of a rightangle triangle whose altitude bears the same relation to its base that the coefficient of friction between the roller and shoe does to one.

4. In a phonic apparatus employing friction in the manner described, a frictionroller having a V-shaped groove in its periphery, a friction-shoe having bearing in said groove, the angle of inclination of the sides of said groove being equal to the acute angle at the base of a right-angle triangle whose altitude bears the same relation to its base that the coeflicient of friction between the roller and shoe does to one.

5. In a phonic apparatus, the combination of a friction-roller havingaperipheral groove, a friction-shoe bearing in said groove, a portion of said shoe being broader than said groove, and primary and secondary vibrating elements in operative relation with said shoe.

6. In a phonic apparatus, the combination of a friction-roll having a peripheral groove, a sectional friction-shoe bearing in said groove one of the sections of said shoe being broader than said groove and one narrower, and primary and secondary vibrating elements in operative relation with said shoe.

7. In a phonic apparatus, the combination of a friction-roller, a friction-shoe bearing thereon, said shoe having a cut-away space or dust-pocket formed in its friction-face and primary and secondary vibrating elements in operative relation with said shoe.

8. In a phonic apparatus, the combination of a friction-roller, a sectional friction-shoe bearing thereon, a flexible connection between the shoe-sections, said connection consisting of a suitably-fulcrumed lever with links pivotally connected thereto and to the shoe-sections, and primary and secondary vibrating elements in operative relation with said shoe.

9. In a phonic apparatus, the combination of primary and secondary vibrating elements, a friction-roller, a friction-shoe section bearing on said roller and having its rear end in operative relation with said primary vibrating element, a second friction-shoe section bearing on said roller and having its front end in operative relation with the secondary vibrating element, a lever fulcrumed in proximity to the adjacent ends of said shoesections, and link connections between said lever and the adjacent ends of said shoesections.

10. In aphonic ap aratus,afriction-roller, a sectional friction-s ioe bearing thereon, a

primary vibrating element in operative relation with one end of said shoe, a secondary vibrating element, and a flexible connection between said secondary element and the other end of said shoe, said connection extending approximately along a line tangent to the friction-roller at a point approximately midway of the length of the shoe-section to which it is connected.

11. In a phone apparatus, the combination of a primary and a secondary vibrating element, a friction-roller, a sectional frictionshoe bearing on said roller, a link connection between the front end of one shoe-section and said secondary vibrating element, said link connection extending along a line approximately tangent to said friction-roller at a point substantially midway between the ends of said shoesection, a lever pivoted inproximity to the adjacent ends of the shoe-sec tions, links connecting said lever to said shoe- In testimony whereof I haye signed this sections, the link connected to the rear shoespecification in the presence of two subscrib- JO section extending along a line approximately ing Witnesses.

tangent to the roller at a point substantially 5 midwaybetween the ends of said section, and DANIEL HIGHAM' operative connections between the primary Witnesses: vibrating element and said last-named shoe- A. B. KEOUGH,

section.

0. A. GIBNER. 

